Your sample request is about how to use the WCF Service to send the big Files. If I misunderstood your requirement, please feel free to let me know.

You can refer the MariusVanBelkum’s link, and if you want the sample, you can refer the following link:
http://code.msdn.microsoft.com/Streaming-Photo-OData-7feb9239.
This sample demonstrates how to use WCF Data Services to implement an OData service that uses a streaming provider to store and retrieve image files.